The present invention relates to multi-unit railway freight cars for carrying intermodal cargo containers, and particularly to such freight cars for carrying cargo containers including equipment requiring an outside source of electric power.
Multi-unit articulated railway freight cars have been used widely in the past several years, and some such cars include a container well in each car unit for receiving one or more cargo containers. Some of such cars are also able to carry at least one additional container stacked atop a container or containers carried in the container well.
Such cargo containers may include equipment such as refrigeration machinery powered by electric motors requiring an external source of electricity, and it is known to carry an engine-driven electric power generator on one unit of a multi-unit freight car to provide electrical power to operate equipment such as refrigeration units included in one or more of the cargo containers carried on any unit of such a car. Such generators are usually included in generator units which include structure to replace a standard cargo container and thus provide support for a cargo container carried atop such a generator unit.
In the past, however, electrical connection from such a generator unit to each cargo container requiring power has been by the provision of an individual power cable extending along the car and intervening cargo containers to each cargo container requiring electrical power. Such electric power cables have thus been located outside the car structure, where they are exposed to possible damage by contact with loaders used to move containers onto or remove containers from freight cars. Such cables, when in place and connected to provide power to equipment included in a cargo container, are still somewhat exposed to the risk of being snagged while the car travels along a railway. Additionally, such cables are exposed to being grabbed as handles by persons intending to climb onto a car or onto a container carried on a car, and there is thus a definite safety hazard involved in such use of individual cables.
Considerable amounts of time and labor are involved in installation or removal of individual cables to carry electrical power from a generator unit to each individual container requiring such electrical power, as the cables must be moved out of the way each time the container-carrying car is loaded or unloaded. Such removal and replacement of cables is not only time-consuming but undesirably expensive, as the cables are exposed to damage or possible theft, and expose the personnel handling them to possible electrical shock or other injury.
Permanently installed receptacles are well known in railway cars for intercar delivery of electrical power through jumper cables as is disclosed in O'Neil U.S. Pat. No. 4,343,522 and Sasgen U.S. Pat. No. 4,017,136.
It is also well known to utilize permanently installed cables in railway passenger cars, to distribute electrical power provided by a generator carried in a remote car, as is disclosed in Melcher U.S. Pat. No. 2,564,121 and Kennedy U.S. Pat. No. 1,908,985.
Stewart U.S. Pat. No. 3,497,707 discloses an interconnection and control system for delivering electric power from a supply system located in an automobile to an associated trailer.
Woods U.S. Pat. No. 2,563,571 discloses an electrical distribution system for interconnecting the auxiliary electrical systems of railroad cars coupled to one another, in order to improve efficiency of the use of electrical power generated on one of a series of interconnected passenger cars.
Logan, Jr., U.S. Pat. No. 2,163,400 discloses a control system for distributing low voltage power for auxiliary use among several cars of an electric train. The disclosure is not related, however, to distribution of electrical power in freight cars for use by equipment carried in cargo containers on such freight cars.
Hamilton U.S. Re. Pat. No. 22,168, a reissue of U.S. Pat. No. 2,153,247, shows a power supply system for providing electricity to several cars of a railroad train from a generator located in one car. The power supply system controls the electric power to make sure that dangerous voltage is not available at car couplers where there are no adjacent cars.
The prior art, however, does not disclose a practical multi-unit container-carrying railway freight car including any convenient system for distributing electrical power from a generator carried in one of the several car units and making the electric power available for use by equipment included in containers carried in any of the several car units. What is desired, then, is a multi-unit railway freight car in which electrical power can be provided to equipment included in cargo containers, with less risk of damage to electrical cables, and with equal or better reliability than has previously been possible, and with a reduced risk of injury to personnel involved with loading, unloading, and operating such a freight car.